A hair cosmetic is used for a variety of purposes, and is used as a hair styling agent for the purpose of hair styling property, a hair treatment agent for the purpose of treatment property, a permanent agent for the purpose of imparting a permanent wave to the hair, a hair dye or a decolorant for the purpose of changing the color of the hair, or the like. Among these hair cosmetics, liquid, creamy, gel-like, spray and foam-like forms are predominant.
These hair cosmetics are used by being applied to the hair, and are required to be capable of being easily applied to the hair uniformly. At the same time, it is also desired that a hair cosmetic does not drip from the hair, does not spatter when applied to the hair, and does not dirty the surrounding, clothing, the skin or the like.
Among the various forms, a liquid hair cosmetic has the characteristic that it is easily applied to the hair, but has a defect that it drips easily. On the other hand, a creamy hair cosmetic has the characteristic that it drips with difficulty, but it has a defect that it is spread with difficulty when applied to the whole hair and hairs are entangled since the cosmetic has high viscosity. A spray hair cosmetic has a defect that spattering to the surrounding or clothing is caused and a specific container equipped with a nozzle which discharges the cosmetic in a spray form is required. Since a foam-like hair cosmetic is foamy, it is applied to the hair in the state where it is diluted with the air. For this reason, in order to make an effective component act at a sufficient concentration, it is required that the concentration of the effective component is enhanced in advance. Furthermore, the hair cosmetic has a defect that a specific container equipped with a nozzle which discharges the hair cosmetic in a foam-like form is required.
Therefore, a hair cosmetic has a problem to be solved that it can be easily applied to the hair uniformly and, at the same time, it does not drip from the hair, does not spatter when applied to the hair, and does not dirty the surrounding, clothing, the skin or the like.
Concerning the problem of a hair cosmetic, for example, in the field of a hair dye or a decolorant aiming at changing the color of the hair, a hair cosmetic which is thickened into a gel by mixing a first agent containing a surfactant in a high concentration with a second agent containing a specific amount of water (e.g. Patent Document 1), and a hair cosmetic which is thickened by mixing a first agent containing an anionic polymer with a second agent containing an alkali agent by utilizing a nature that the anionic polymer is thickened under an alkaline condition (e.g. Patent Document 2) are known.
Patent Document 1 describes a hair dye composition which is gelled and thickened by mixing a first agent containing a surfactant in a high concentration with a second agent containing a specific amount of water. In this hair dye composition, when the first agent containing a surfactant in a high concentration contains water in an amount exceeding a given amount, the first agent itself is thickened, and therefore a lower alcohol such as ethanol or isopropanol is contained in the first agent in an amount around 5 to 30%. As described above, since the first agent contains a large amount of the lower alcohol and the surfactant, the cost may be increased, the hair may be defatted excessively by hair dyeing, the hair may be damaged and dried, and the hair may come to have a rough feeling. Further, since the amount of water contained in the first agent is small, a precipitate may be generated and storage stability may be deteriorated, depending on the solubility of the dye.
Patent Document 2 describes a two-pack type oxidation hair dye and a two-pack type decolorant which are thickened by mixing a first agent containing an alkali agent with a second agent containing an anionic polymer such as an acrylic acid-methacrylic acid copolymer as a thickener. In these two-pack type oxidation hair dye and two-pack type decolorant, usually the first agent and the second agent can be easily mixed with each other since both of them are liquid, and the resultant mixed liquid has such a viscosity that it is easily applied to the hair by the effect of the anionic polymer. However, the use of the anionic polymer may make the hair creaky and rough.
Furthermore, a foamy hair cosmetic which is obtained by shaking a first agent and a second agent upon mixing, thereby giving a foamy agent (e.g. Patent Document 3) is also known. Patent Document 3 describes a hair cosmetic which is a hair dye or a decoloring and destaining agent, that is formulated into a foamy dosage form by a foaming operation of foaming a first agent and a second agent by shaking upon use. This hair cosmetic is in a foamy dosage form, and is applied to the hair in the state where the hair cosmetic is diluted with the air. For this reason, in order to obtain a decoloring effect or a hair dyeing effect which is comparable with that of a liquid or gel-like hair cosmetic, the concentration of an alkali agent or a dye should be increased in advance since the hair cosmetic is applied to the hair after being diluted with the air. In addition, the hair cosmetic contains the alkali agent or the dye in high concentrations, which results in that breakage of the hair or damage of the hair may become severe.